Transcript GPS Global Positioning System

What is GPS?
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Global positioning receivers
Satellite-based
navigation/positioning
system
Developed by the US Dept. of
Defense (DOD)
World-wide coverage 24
hours a day
24 operational satellites
Minimum of 4 satellites in
view at any one time
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The global positioning system (GPS) has 24
satellites in known orbits that broadcast radio
signals to Earth.
A hand held GPS unit analyzes these signals
and determines the user’s current position.
The GPS unit (receiver) determines the travel
time of a signal from a satellite by comparing
the code it is generating, with an identical code
from the satellite
The distance is calculated using: distance =
velocity * time
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A GPS unit finds the distance to each satellite
by measuring how long that satellite’s radio
signal take to reach the receiver.
The point where the distance to at least 3
satellites intersect is the user’s location.
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Today’s receivers are extremely accurate thanks to
a new design.
Those with WAAS (Wide Area Augmentation
System) can improve accuracy to less than 3 meters
on average (approximately 9 feet).
WAAS was developed by the Federal Aviation
Administration and the Department of
Transportation.
It is a system of geostationary satellites and
ground stations across the US that provide real
time GPS signal corrections.
It’s available to all WAAS enabled GPS receivers.
Those without it, may only be accurate to within 15
meters on average (approx. 45 feet) at best.
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A selected point of
interest location that
can be saved, stored
and recalled from a
GPS’s receiver’s
memory. Cache
locations are saved as
waypoints
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Press the page button and switch to the menu
page.
Press the up or down button and highlight the
mark field.
Press enter. The mark waypoint page appears
with ok highlighted.
Note: as a shortcut, press and hold enter to
mark a waypoint.
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Press and hold enter to mark a waypoint.
Press the up or down button and highlight the
coordinates at the bottom of the screen.
Use the up or down buttons to move across the
numbers. Press enter to update a number.
Press the up or down button to select the
number and enter to accept it.
When you have updated the coordinates, press
the up button to highlight ok?
Press enter to save the new coordinates.
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Press the page button and switch to the menu
page.
Press the up or down button and highlight find.
Press enter. The Find page appears. Select
Waypoints.
Press the up or down button and select the tab
containing the desired coordinates and press enter.
Press the up or down button to select the desired
coordinates and press enter.
The review waypoint page appears. Press the up
or down button to highlight GOTO, and press
enter.